[Swordmaker]

I just got my iPhone 4 this past weekend and I love it. Verizon has excellent connectivity and network speed. Verizon’s network speed is far higher than AT&Ts. For the apps I use, and they are fairly heavy weight data apps, the difference is night and day. The iPhone 4 has significant improvements of over the iPhone 3GS and was worth the cost.

Actually, CodeToad, AT&T's 3G is faster than Verizon's... almost twice as fast. AT&T doesn't have the depth of penetration of it's 3G that Verizon has, nor has it rolled out as much 3.75G (called 4G by both, even though it is not) as Verizon has... but neither the AT&T nor the Verizon iPhone4 can utilize any of the 4G networks on either carrier, that will have to wait for the iPhone5.

The iPhone4 itself is twice as fast as the 3Gs.

[CodeToad]

It might be theoretically faster, but not in practice.

[CodeToad]

P.S. Two of us did side-by-side comparisons for the same small and large data sets. The Verizon finished over 4 times faster in every case. This is important to us as we design systems requiring large updates, 240MB to 2.2GB, every 28 days for our users.